Chemical acid gas treatment system

Abstract

The utility model relates to a chemical acid gas treatment system, comprising: a quenching unit for cooling high-temperature chemical acid gas; the treatment unit is used for receiving the solid treatment object and the chemical acid gas from the quenching unit, and mixing and contacting the chemical acid gas and the solid treatment object to generate a treated gas-solid mixture; the separation unit is used for receiving the treated gas-solid mixture from the treatment unit and separating a product solid in the treated gas-solid mixture from the treated gas; and a circulation unit receiving the product solids from the separation unit and conveying a portion of the product solids as a circulation solid treatment material back to the treatment unit, where the treatment unit includes a solids addition portion disposed at a lower portion thereof for adding fresh solid treatment material to the treatment unit. According to the chemical acid gas treatment system, the utilization rate of the solid treated matter can be increased, so that the cost is reduced.

Description

Technical Field

[0001] The present application relates to a system for treating chemical industrial acidic gas using solid treatment materials, and more particularly, to a chemical industrial acidic gas treatment system that at least partially recycles the solid treatment materials. Background Art

[0002] In the treatment of chemical industrial acidic gas, a reactor is usually arranged between a separation device and a quenching device, and solid treatment materials are added thereto to perform neutralization reaction, adsorption, etc. on acidic gas, heavy metals, dioxins, etc. in the gas. Since the mixing contact time between the solid treatment materials and the acidic gas is short, the participation rate of the solid treatment materials in the treatment is low (for example, the reaction conversion rate and / or adsorption saturation is about 30%), resulting in a large amount of solid treatment materials not participating in the treatment. After being separated and collected in the separation device, they enter a solid hazardous waste landfill for landfill disposal. This not only wastes the solid treatment materials, making the cost of acidic gas treatment relatively high, but also increases the cost of solid waste landfill and wastes the resources of the landfill.

[0003] Therefore, there is a need to develop a chemical industrial acidic gas treatment system that can more efficiently utilize solid treatment materials. Summary of the Utility Model

[0004] The present application provides a chemical industrial acidic gas treatment system that at least partially solves the above problems, and particularly recycles the solid treatment materials used for treating acidic gas, thereby improving the utilization rate of the solid treatment materials, reducing costs and reducing the amount of solid waste.

[0005] According to one aspect of the present application, the chemical industrial acidic gas treatment system includes: a quenching unit for cooling high-temperature chemical industrial acidic gas; a treatment unit that receives solid treatment materials and chemical industrial acidic gas from the quenching unit and is used to mix and contact the chemical industrial acidic gas with the solid treatment materials to produce a treated gas-solid mixture; a separation unit that receives the treated gas-solid mixture from the treatment unit and is used to separate the product solid in the treated gas-solid mixture from the treated gas; and a recycling unit that receives the product solid from the separation unit and conveys a part of the product solid as recycled solid treatment materials back to the treatment unit. The chemical industrial acidic gas treatment system according to the present application uses the recycling unit to cyclically convey the product solid that has participated in the treatment back to the treatment unit to participate in secondary or more treatments, thereby further utilizing the materials in the product solid that have not participated in the reaction and / or are not adsorbed saturated, and improving its utilization rate. In some examples, the treatment unit includes a solid addition part arranged at its lower part for adding fresh solid treatment materials that have not participated in the treatment and are used to participate in the treatment of chemical industrial acidic gas, and the solid treatment materials include fresh solid treatment materials and recycled solid treatment materials. It can be understood that the fresh solid treatment materials supplement the amount required for the recycled product solid that is insufficient to treat acidic gas.

[0006] In some examples, the recycling unit includes: a receiving part disposed below the separation unit to receive the product solids from the separation unit; a distributing part disposed downstream of the receiving part to divert the product solids into recycled solid treats and discarded product solids; a grinding part disposed downstream of the distributing part to apply grinding to the recycled solid treats; and a delivering part disposed downstream of the grinding part and at least partially extending into the processing unit to deliver the ground recycled solid treats into the processing unit. After the separation unit separates the processed gas-solid mixture, the recycling unit receives the separated product solids, distributes a part for discarding, recycles the other part, grinds the recycled part, and cyclically delivers it back to the processing unit to participate in the acid gas treatment again.

[0007] In some examples, the distributing part includes a regulating element that detects a pollution index of the processed gas and, in response to the pollution index not reaching the target pollution index, increases the proportion of discarded product solids in the product solids and / or, in response to the pollution index being better than the target pollution index by more than a first threshold, decreases the proportion of discarded product solids in the product solids. By adjusting the ratio of discarded product solids to recycled solid treats and correspondingly supplementing fresh solid treats, the ratio of recycled solid treats to fresh solid treats in the solid treats provided to the processing unit can be changed, thereby adjusting the acid gas treatment capacity to reduce the consumption of solid treats while meeting the treatment standards.

[0008] In some examples, the recycling unit further includes an analyzing part disposed between the grinding part and the delivering part and configured to analyze the density of the product solids to estimate the ratio of the solids that have participated in the treatment to the solids that have not participated in the treatment in the product solids. In response to the ratio of the solids that have participated in the treatment to the solids that have not participated in the treatment exceeding a second threshold, the distributing part is configured to reduce the proportion of the product solids diverted into recycled solid treats, and the solid adding part is configured to increase the amount of fresh solid treats added. When the proportion of the reacted and / or adsorbed saturated solids in the product solids is too high, that is, the proportion of the solids in the recycled solid treats is too high, the recycling ratio can be reduced and the amount of fresh solid treats can be supplemented to improve the acid gas treatment capacity.

[0009] In some examples, the distributing part is configured to make the ratio of the product solids diverted into recycled solid treats and discarded product solids between 1:9 and 9:1 to balance the utilization rate of the solid treats and the acid gas treatment capacity.

[0010] In some examples, the delivery portion includes distribution holes located on the portion of the delivery portion extending inside the processing unit for distributing the circulating solid treatment material into the processing unit for more uniform mixing and more sufficient reaction and / or adsorption with the acid gas. In some examples, the delivery portion further includes a vibration element to prevent the circulating solid treatment material from caking, thereby improving its dispersion above the delivery portion.

[0011] In some examples, at least part of the circulation unit is arranged to be isolated from the atmosphere to isolate water and acid gas in the atmosphere, and includes a heating element to at least partially remove water in the circulating solid treatment material to reduce losses and moisture of the circulating solid treatment material during transportation.

[0012] In some examples, the chemical acid gas treatment system further includes a drying unit arranged between the processing unit and the separation unit to at least partially remove water in the treated gas-solid mixture, thereby enhancing the gas-solid separation effect of the separation unit and enabling the separated product solid to be more smoothly discharged from below the separation unit.

[0013] In some examples, the processing unit is a dry reactor, and the separation unit is a bag filter. The chemical acid gas inlet is located at the bottom of the dry reactor, the gas-solid mixture outlet is located at the top of the dry reactor, and the delivery portion is located above the chemical acid gas inlet. In other examples, these units can also adopt other types of reactors, separation equipment, etc. commonly used in the chemical industry, and appropriate positions and connection relationships. Description of the Drawings

[0014] Figure 1 is a schematic block diagram of a chemical acid gas treatment system according to an embodiment of the present application.

[0015] Reference numerals: 100 - quench unit; 200 - processing unit; 220 - solid addition portion; 300 - separation unit; 400 - circulation unit; 410 - receiving portion; 420 - distribution portion; 422 - regulating element; 440 - grinding portion; 460 - analysis portion; 480 - delivery portion. Detailed Description of the Embodiment

[0016] The chemical acid gas treatment system according to an embodiment of the present application will be described below with reference to the accompanying drawings. Figure 1 The positions, sizes, and connection sequences of the various units, portions, and elements are schematically shown, without representing the actual or necessary positional relationships, relative sizes, or connection sequences of these units, portions, and elements. Those of ordinary skill in the art can make reasonable adjustments and changes to the positional relationships, relative sizes, or connection sequences of these units, portions, and elements based on reading this application without departing from the teachings of this application.

[0017] Figure 1 is a schematic block diagram of a chemical acid gas treatment system according to an embodiment of the present application. As Figure 1 shown, in some embodiments, the chemical acid gas treatment system according to an embodiment of the present application includes a quench unit 100, a treatment unit 200, a separation unit 300, and a recycle unit 400. The quench unit 100 is used to cool the high-temperature chemical acid gas so as to be provided to the treatment unit 200 for treatment. The treatment unit 200 is used to receive a solid treatment material and the chemical acid gas from the quench unit 100, and cause the chemical acid gas to come into mixed contact with the solid treatment material to generate a treated gas-solid mixture. As an example, the chemical acid gas may include, for example, acidic reactive substances such as sulfur dioxide, hydrogen sulfide, nitrogen oxides, hydrochloric acid, etc. In this case, an alkaline solid treatment material can be selected to react and neutralize with it, so as to remove at least part of these acidic reactive substances from the waste gas. As an example, slaked lime (i.e., calcium hydroxide) powder can be used as the solid treatment material to react with these acidic reactive substances, so that they are neutralized and removed from the waste gas. In some embodiments, in addition to chemically reacting with the reactive components in the chemical acid gas, the solid treatment material also physically adsorbs the particles and harmful gases in the chemical acid gas. As an example, the solid treatment material may also include a physical adsorbent such as activated carbon to adsorb harmful components such as dioxins. It should be understood that slaked lime and activated carbon are only exemplary solid components for acid waste gas treatment, and other solid components known in the art or yet to be developed can also be used to carry out neutralization reactions and physical adsorption on acid waste gas.

[0018] In some embodiments, the treatment unit 200 is a dry reactor. The chemical acid gas cooled by the quench unit 100 enters from the bottom of the dry reactor, and the treated gas-solid mixture is discharged from the top of the dry reactor. In other embodiments, the treatment unit can also be other common reactors known in the chemical industry, such as tubular reactors and bed reactors, etc., and correspondingly set the gas inlet, the solid treatment material inlet, and the gas, solid, and / or gas-solid mixture outlet, and be correspondingly configured for continuous treatment or batch treatment. In some embodiments, the treatment unit 200 includes a solid addition part 220 provided at its lower part to add fresh solid treatment material that has not participated in the treatment for participating in the treatment of the chemical acid gas into the treatment unit 200. In this case, it can be understood that the solid treatment material for treating the chemical acid gas in the treatment unit 200 includes fresh solid treatment material and recycled solid treatment material, and the two can be added into the treatment unit 200 at the same or different positions in the treatment unit 200. Compared with the chemical acid gas treatment system without recycling, the consumption of fresh solid treatment material of the chemical acid gas treatment system according to the present application can be reduced by 50% - 70%, and similar treated gas pollution indexes can be achieved.

[0019] The separation unit 300 is configured to receive the processed gas-solid mixture from the processing unit and separate the product solids in the processed gas-solid mixture from the processed gas. In the context of the present application, the product solids refer to the products after the solid treatment material participates in the chemical acid gas treatment at the processing unit 200, regardless of whether the solid treatment material comes from freshly added solid treatment material, recycled solid treatment material, or a combination of both. In some embodiments, the separation unit 300 may be a bag filter, which uses filter bags made of materials such as fabric or non-woven fabric to separate and collect the solid particles in the gas-solid mixture from the gas, discharge the gas, and collect the solid particles as product solids at the bottom of the bag filter. In other embodiments, the separation unit 300 may also be other common gas-solid separation devices in the chemical industry, such as a cyclone separator.

[0020] The product solids collected at the separation unit 300 are transported to the recycling unit 400. The recycling unit 400 receives the product solids and transports a portion of the product solids back to the processing unit as recycled solid treatment material, while treating the other portion of the product solids as solid waste, such as landfill. Without being limited by any theory, the utilization rate of the solid treatment material passing through the processing unit 200 once may be low. For example, the reaction rate of the basic solid treatment material used to react with the acid-reactive substances in the chemical acid gas is low, or the adsorption saturation of the adsorbent is low. Therefore, if the solid treatment material after one treatment is directly discarded, it will cause a large amount of waste, increase the cost of solid waste disposal, and increase the environmental pollution caused by solid waste. In contrast, the chemical acid gas treatment system according to the present application can recycle at least part of the product solids, so that the unutilized basic solid treatment material and adsorbent can repeatedly contact the chemical acid gas at the processing unit 200, thereby improving the utilization rate of the solid treatment material.

[0021] In some embodiments, the circulation unit 400 of the chemical acid gas treatment system according to the present application includes a receiving portion 410, a distribution portion 420, a grinding portion 440 and a delivery portion 480. The receiving portion 410 is arranged below the separation unit 300 to receive the product solids from the separation unit 300. In some embodiments, the receiving portion 410 is a screw conveyor or a conveyor belt. The distribution portion 420 is arranged downstream of the receiving portion 410 to divert the product solids into circulating solid treatment materials and discard the product solids. As will be described in more detail later, the diversion ratio can be adjusted according to the pollutant content of the treated gas and / or the ratio of reacted / unreacted substances in the product solids and / or the ratio of adsorbed saturated / unadsorbed saturated substances, so as to simultaneously meet the purpose of meeting the gas treatment standards and reducing the waste of solid treatment materials. The grinding portion 440 is arranged downstream of the distribution portion 420 to grind the circulating solid treatment materials to at least partially eliminate the agglomeration in the circulating solid treatment materials and increase the contact area. The delivery section 480 is arranged downstream of the grinding section 440 and at least partially extends to the interior 200 of the processing unit to deliver the ground circulating solid processed material back to the interior of the processing unit 200, so as to participate in the treatment of chemical acid gas again. In some embodiments, the delivery section 480 can be located above the inlet of the chemical acid gas so that the circulating solid processed material is blown by the upward airflow and fully mixed with it. In some embodiments, the delivery section 480 can be a screw conveyor or a conveyor belt. The distribution section 420 can adopt a common mechanical structure in the art to achieve diversion. As an example, the distribution section 420 can include a movable baffle plate arranged at its outlet to change the proportion of diversion to the circulating solid processed material side and the discarded product solid side by adjusting the position of the baffle plate.

[0022] In some embodiments, the dispensing portion 420 includes an adjustment element 422. Figure 1As shown by the dashed arrow A in [description], the regulating element 422 detects the pollution index of the treated gas discharged from the separation unit 300, such as the content of acidic gas or other pollutants. As an example, when the regulating element 422 detects that the pollution index of the treated gas does not reach the target pollution index (for example, the content of acidic gas is too high), the regulating element 422 adjusts the shunt ratio of the distribution part 420 to increase the proportion of discarded product solids in the product solids collected from the separation unit 300. It can be understood that in this case, the solid addition part 220 can correspondingly increase the amount of fresh solid treatment material added, so as to increase the concentration of unreacted basic reactants and unsaturated adsorbents participating in the chemical acidic gas in the treatment unit 200, thereby improving the treatment capacity of the chemical acidic gas and making the pollution index of the treated gas meet the standard. As another example, when the regulating element 422 detects that the pollution index is better than the target pollution index by more than the first threshold (for example, the content of acidic gas is less than 50% of the emission standard, etc.), the proportion of discarded product solids in the product solids is reduced to avoid waste caused by excessive discarding of product solids and too little recycled product solids. In some embodiments, the regulating element 422 may include a detection device (not shown) for detecting the pollution index of the treated gas, a processing device (not shown) for determining the shunt ratio based on the pollution index, and a communication device (not shown) for sending the determined shunt ratio to the structure of the distribution part 420 to actually perform the shunt, and these devices can be implemented by various sensor devices, computing processing devices, and communication devices known or yet to be developed in the art.

[0023] In some embodiments, the recycling unit 400 further includes an analysis section 460. The analysis section 460 is disposed between the grinding section 440 and the delivery section 480 for analyzing the density of the product solids, thereby estimating the ratio of the solids that have participated in the treatment to the solids that have not participated in the treatment in the product solids. In some embodiments, when the ratio of the solids that have participated in the treatment to the solids that have not participated in the treatment exceeds a second threshold (e.g., 9:1), the distribution section 420 is configured to reduce the ratio of the product solids diverted as recycled solid treatment materials, and the solid addition section 220 is configured to increase the amount of fresh solid treatment materials added. Without being limited by any theory, by way of example, when treating sulfur dioxide-containing gas with a solid treatment material containing slaked lime, the two react to form water and calcium sulfite, thereby making the apparent density of the solids different from that of fresh slaked lime. In one instance, when the acidic gas contains only sulfur dioxide or is mainly sulfur dioxide, the apparent density of the generated calcium sulfite is lower than that of fresh slaked lime. Accordingly, if the apparent density of the product solids has been low enough to be close to the apparent density of calcium sulfite, it can be inferred that the content of unreacted slaked lime therein is already small. In this case, the analysis section 460 can cause the distribution section 420 to change the diversion ratio to increase the ratio of discarded product solids in the product solids collected from the separation unit 300, and replenish fresh solid treatment materials in the solid addition section 220 to avoid a reduction in the gas treatment capacity due to excessive recycling of the product solids. In addition, a small content of unreacted slaked lime in the product solids means that the treatment capacity of the recycled solid treatment materials for the acidic gas has been low, and recycling a large amount of recycled solid treatment materials with low treatment capacity will also result in an increase in energy consumption. Accordingly, appropriately increasing the ratio of discarded product solids can reduce the amount of recycled solid treatment materials and correspondingly reduce the recycling energy consumption. In other embodiments, the slaked lime or other alkaline reactive solids may also increase in density after reacting with the acidic gas, and the water generated by the reaction and / or the substances adsorbed by the adsorbent may also affect the density of the solid product. In an alternative embodiment, the densities at various known ratios of the solids that have participated in the treatment to the solids that have not participated in the treatment can be sampled and measured, and a working curve can be made as a reference for the analysis section 460 to estimate the ratio based on the density of the product solids.

[0024] In some embodiments, the distribution section 420 is configured to make the diversion ratio of the product solids diverted as recycled solid treatment materials and discarded product solids between 1:9 and 9:1, such as 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, etc. By adjusting the diversion ratio, the consumption of the solid treatment materials and the corresponding costs can be reduced on the premise of meeting the standard for chemical acidic gas treatment. As described above, the diversion ratio can be adjusted based on factors such as the effect of chemical acidic gas treatment and / or the ratio of the solids that have participated in the treatment to the solids that have not participated in the treatment in the product solids.

[0025] In some embodiments, the delivery portion 480 includes distribution holes (not shown). The distribution holes are located on the portion of the delivery portion 480 that extends inside the processing unit 200 for distributing the recycled solid treatment material into the processing unit 200. As an example, the delivery portion 480 may include a conveyor belt, and the distribution holes may be arranged at the end of the conveyor belt. In some embodiments, the delivery portion 480 further includes a vibration element (not shown) to improve the dispersion of the recycled solid treatment material over the delivery portion 480, thereby improving the mixing contact between the recycled solid treatment material and the chemical acidic gas.

[0026] In some embodiments, at least part of the recycling unit 400 is arranged to be isolated from the atmosphere to prevent the influence of water and / or acidic gases such as carbon dioxide in the atmosphere on the solid treatment material. In some embodiments, the recycling unit 400 further includes a heating element (not shown) to at least partially remove the water in the recycled solid treatment material. As an example, the heating element may be arranged between the dispensing portion 420 and the grinding portion 440 and / or between the grinding portion 440 and the delivery portion 480.

[0027] In some embodiments, the chemical acidic gas treatment system further includes a drying unit (not shown) arranged between the processing unit 200 and the separation unit 300 to at least partially remove the water in the treated gas-solid mixture, thereby improving the separation effect of the separation unit 300 on the treated gas and the solid product and avoiding adhesion.

[0028] The chemical acidic gas treatment system according to the present application reduces the operating cost of a system for treating chemical waste by means of incineration, improves the effective utilization rate of the solid treatment material, and reduces the generation of solid waste (such as fly ash) as hazardous waste. It has good economic and environmental benefits. Taking a system in which the acidic gas generated by the incineration of 100 tons / day of chemical hazardous waste is treated by a solid treatment material mainly composed of slaked lime as an example, in the case of a treatment system without solid treatment material recycling, the effective utilization rate of slaked lime is only about 30%, the actual slaked lime addition amount is 76 kg / h, and the actual fly ash discard amount is 327 kg / h. Under the condition of a 500% high reflux ratio, the actual slaked lime addition amount is 28 kg / h, the actual fly ash recycling amount is 1396 kg / h, and the actual fly ash discard amount is 279 kg / h. The slaked lime consumption is reduced by 64%, and the fly ash discard amount is reduced by 15%. The annual operating cost is reduced by about 650,000 yuan.

[0029] The chemical acid gas treatment system according to the present application has been described above in conjunction with the embodiments and illustrations. These embodiments and illustrations present some exemplary implementations, and do not indicate that the included features are the preferred or necessary features of the chemical acid gas treatment system according to the present application. Those of ordinary skill in the art can make modifications and variations to the described embodiments without departing from the teachings of the present application.

Claims

1. A chemical acid gas treatment system, characterized in that, The chemical acid gas treatment system includes: A quench unit configured to cool down the high-temperature chemical acid gas; A treatment unit that receives a solid treatment material and the chemical acid gas from the quench unit, and causes the chemical acid gas to come into mixed contact with the solid treatment material to produce a treated gas-solid mixture; A separation unit that receives the treated gas-solid mixture from the treatment unit and separates the product solid in the treated gas-solid mixture from the treated gas; A recycling unit that receives the product solid from the separation unit and conveys a part of the product solid back to the treatment unit as a recycled solid treatment material, where The treatment unit includes a solid addition part provided at its lower part, and the solid addition part adds fresh solid treatment material that has not participated in the treatment for treating the chemical acid gas to the treatment unit, and wherein the solid treatment material includes the fresh solid treatment material and the recycled solid treatment material.

2. The chemical acid gas treatment system according to claim 1, characterized in that, The recycling unit includes: A receiving part provided below the separation unit to receive the product solid from the separation unit; A distribution part provided downstream of the receiving part to split the product solid into the recycled solid treatment material and discarded product solid; A grinding part provided downstream of the distribution part to apply grinding to the recycled solid treatment material; A delivery part provided downstream of the grinding part and at least partially extending into the treatment unit to deliver the ground recycled solid treatment material into the treatment unit.

3. The chemical acid gas treatment system according to claim 2, characterized in that, The distribution part includes an adjustment element that detects a pollution index of the treated gas, and increases the proportion of discarded product solid in the product solid in response to the pollution index not reaching the target pollution index and / or reduces the proportion of the discarded product solid in the product solid in response to the pollution index being better than the target pollution index by more than a first threshold.

4. The chemical acid gas treatment system according to claim 2, characterized in that, The recycling unit further includes an analysis part provided between the grinding part and the delivery part and configured to analyze the density of the product solid to estimate the proportion of the solid that has participated in the treatment and the solid that has not participated in the treatment in the product solid, where in response to the proportion of the solid that has participated in the treatment and the solid that has not participated in the treatment exceeding a second threshold, the distribution part is configured to reduce the proportion of the product solid split into the recycled solid treatment material, and the solid addition part is configured to increase the amount of fresh solid treatment material added.

5. The chemical acid gas treatment system according to claim 4, characterized in that, The distribution part is configured to make the proportion of the product solid split into the recycled solid treatment material and the discarded product solid be between 1:9 and 9:

1.

6. The chemical acid gas treatment system according to claim 2, wherein, The delivery part includes distribution holes located on the part where the delivery part extends into the treatment unit to distribute the recycled solid treatment material into the treatment unit.

7. The chemical acid gas treatment system according to claim 2, wherein, The delivery part further includes a vibration element configured to disperse the recycled solid treatment material above the delivery part.

8. The chemical acid gas treatment system according to claim 1, wherein At least part of the recycling unit is arranged to be isolated from the atmosphere and includes a heating element to at least partially remove the water in the recycled solid treatment material.

9. The chemical acid gas treatment system according to claim 1, characterized in that, The chemical acid gas treatment system further includes a drying unit, which is arranged between the treatment unit and the separation unit to at least partially remove water in the treated gas-solid mixture.

10. The chemical acid gas treatment system according to claim 2, wherein The treatment unit is a dry reactor, and the separation unit is a bag filter. The chemical acid gas inlet is located at the bottom of the dry reactor, the gas-solid mixture outlet is located at the top of the dry reactor, and the delivery part is located above the chemical acid gas inlet.

Images